A generator of various DC voltages has already been known from patent application EP 0 176 823. This document describes a diode rectifier circuit applied to an AC voltage produced by the secondary winding of a transformer whose primary winding is connected to the standard distribution network.
For supplying two opposite-sign DC voltages of which one has a different value from the other, the circuit either comprises two AC voltages coming from two secondary windings of the transformer and a single rectifier formed by four diodes and two capacitors plus coupling capacitors, or the circuit comprises a single AC voltage coming from a single secondary winding and two rectifier circuits arranged in series or in parallel, for which eight diodes and four capacitors are necessary, excluding extra capacitors.
This device is not entirely integrable; it needs to have a connection to the AC network and the use of a cumbersome transformer and, furthermore, the circuit itself will comprise an increased number of components if the dimension of the transformer is reduced.